A long felt need in the building wall panel field has been a prefabricated wall panel having either a finished exterior facing adapted for use as an exterior load bearing or non-load bearing wall on commercial buildings, such as multistory apartments or the like, or a wall panel having both major surfaces finished and adapted for use as an interior load bearing wall or non-load bearing partition for such buildings. The fire codes for many commercial buildings prohibit the use of flame transmitting materials in the construction of exterior and interior wall panels, consequently any wall panel adapted for such use must be fabricated from non-flammable material to conform to these codes. In addition to having the above qualities, the ideal wall panel should be capable of being prefabricated as large multistory or multibay panels to minimize on-site construction time. This of necessity requires that the panels have sufficient strength such that they may span relatively large distances, typically twenty feet, without the need of expensive and heavy supporting structures attached to the buildings.
A wall panel having finished surfaces on both sides is shown by Balduf, U.S. Pat. No. 2,241,338. Balduf discloses a structure having a facing of plasterboard or gypsum board secured to one side of a frame formed from a plurality of metal studs. A relatively thin layer of plaster overlays the plasterboard on both sides of the frame. The structure as disclosed by Baldulf is not well adapted to prefabrication since the plasterboard is attached to the metal frame after the metal frame is secured within a building. In addition, the thin layer of plaster overlaying the plasterboard is affixed to the plasterboard after the partition is placed within the structure, thereby requiring time consuming, onsite fabrication to produce the finished partition. The Balduf partition is also not well adapted for exposure to an external environment. The relatively thin layer of plaster is easily cracked when exposed to high tensil and twisting forces such as are encountered on the exterior surface of a building. When exposed to normal weather cycles, the layer of plaster may easily separate from the underlying plasterboard.
Another wall panel, shown by Martin, U.S. Pat. No. 3,885,008, has an external molded panel bonded to a frame constructed from wood. The external molded panel is formed from a plastic compound and is bonded to the wooden frame by overlaying the entire back surface of the molded panel and the sides of the adjacent frame members with a layer of fiberglass reinforced plastic. This wall panel has inherent structural as well as durability limitations. For example, the attachment of a rigid plastic produces a wall panel with an external surface subject to cracking and separation from the underlying wooden frame when exposed to the tensil and twisting forces occurring in a multistory structure. In addition, the inherent structural weakness of the underlying wooden frame generally prohibits prefabricating such a wall panel into a single large multistory panel. Since the plastic exterior molded panel, the bonding compound securing the molded panel to the wooden frame, and the wooden frame itself, are all flammable materials, the panel as disclosed by Martin would not satisfy the fire codes for commercial structures. If the wooden frame of Martin were replaced by a metal frame, Martin would then have a problem of bonding the rigid external plastic molded panel to a frame having more flexure than the wooden frame. In such a situation, when the frame flexed, the bonding would likely break, resulting in the separation of the molded panel from the frame. In addition, the underlying metal frame generally would weigh more than the relatively thin molded panel thereby contributing to the cracking or breaking of the external molded panel.
The present invention overcomes these problems of the prior art by providing a building wall panel having an exterior facing formed from a glass fiber reinforced concrete bonded to a metal frame, formed from a plurality of vertical members, at intervals along the length of the vertical members. The bonding is provided by a glass fiber reinforced concrete similar to that used in forming the exterior facing. The use of a glass fiber reinforced exterior facing provides a building wall panel which is particularly well adapted for exposure to an external environment since such a facing has wear characteristics similar to those of concrete. The use of the metal frame as the supporting structure for such an exterior facing provides a wall panel having high tensil strength and one which can span large distances without the need of expensive support members affixed to the structure. Bonding the exterior facing to the metal vertical members at intervals along the length of each member provides a building wall panel which is particularly well adapted for prefabrication. The building wall panel employs materials which are neither flammable nor exhibit flame transmitting characteristics and thus the wall panel of the present invention conforms to the fire codes required for commercial structures. If the building wall panel of the present invention conforms to the fire codes required for commercial structures. If the building wall panel of the present invention is to be used as an interior wall or partition, a layer of gypsum board, dry wall, or the like may be easily and quickly attached to one side of the frame, such as by the use of self-tapping screws or the like and covered with a plaster faced tape producing a prefabricated wall panel having both surfaces finished. In situations where required, a layer of insulation may be easily attached to the wall panel between adjacent vertical members prior to attaching the layer of gypsum board.